With the understanding that malignancies can usurp immune checkpoint pathways such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed-death 1 (PD-1) as a mechanism of immune escape, immune checkpoint blockade was developed as a therapeutic strategy that has been shown to be effective in many solid tumors such as melanoma, non-small lung cancer, renal cell cancer, and urothelial cancer [61, 62]. Here, CTLA4 is linked to melanoma.